#include <stdio.h>
#include <string.h>


int main(void)
{
    char name[ ] = "Jack_Tang";
    printf("Hello, %s!\n", name);
    printf("The length of name is %d\n", (int)sizeof(name));

    char name2[20];
    strcpy(name2, " is a good boy ");
    printf("%s\n", name2);
    printf("The length of name2 is %d\n", (int)strlen(name2));

    char name3[20];
    strcpy(name3, name);
    strcat(name3, name2);
    printf("%s\n", name3);

    printf("The length of name3 is %d\n", (int)strlen(name3));

    scanf("%s", name3);
    if(strcmp(name3, "Jack_Tang") == 0){
        printf("Hello, Jack_Tang!\n");
    }else{
        printf("Who are you?\n");
    }

    return 0;
}